Department of Botany and Microbiology, University of Oklahoma, 770 Van Vleet Oval GLCH 135, Norman, OK 73019, USA.
Appl Microbiol Biotechnol. 2011 Aug;91(4):1083-93. doi: 10.1007/s00253-011-3326-z. Epub 2011 May 12.
Nine wells producing from six different reservoirs with salinities ranging from 2.1% to 15.9% were surveyed for presence of surface-active compounds and biosurfactant-producing microbes. Degenerate primers were designed to detect the presence of the surfactin/lichenysin (srfA3/licA3) gene involved in lipopeptide biosurfactant production in members of Bacillus subtilis/licheniformis group and the rhlR gene involved in regulation of rhamnolipid production in pseudomonads. Polymerase chain reaction amplification, cloning, and sequencing confirmed the presence of the srfA3/licA3 genes in brines collected from all nine wells. The presence of B. subtilis/licheniformis strains was confirmed by sequencing two other genes commonly used for taxonomic identification of bacteria, gyrA (gyrase A) and the 16S rRNA gene. Neither rhlR nor 16S rRNA gene related to pseudomonads was detected in any of the brines. Intrinsic levels of surface-active compounds in brines were low or not detected, but biosurfactant production could be stimulated by nutrient addition. Supplementation with a known biosurfactant-producing Bacillus strain together with nutrients increased biosurfactant production. The genetic potential to produce lipopeptide biosurfactants (e.g., srfA3/licA3 gene) is prevalent, and nutrient addition stimulated biosurfactant production in brines from diverse reservoirs, suggesting that a biostimulation approach for biosurfactant-mediated oil recovery may be technically feasible.
从六个不同的储层中抽取了九个产油井，这些储层的盐度范围从 2.1%到 15.9%，以检测是否存在表面活性化合物和产生生物表面活性剂的微生物。设计了简并引物来检测芽孢杆菌/地衣芽孢杆菌群成员中涉及脂肽生物表面活性剂生产的表面活性素/lichenysin（srfA3/licA3）基因和假单胞菌中涉及 rhamnolipid 生产调控的 rhlR 基因的存在。聚合酶链反应扩增、克隆和测序证实了从所有九个井中采集的盐水中存在 srfA3/licA3 基因。通过对通常用于细菌分类鉴定的两个其他基因（gyrA（gyrase A）和 16S rRNA 基因）进行测序，证实了芽孢杆菌/地衣芽孢杆菌菌株的存在。在任何盐水样品中都没有检测到与假单胞菌相关的 rhlR 或 16S rRNA 基因。盐水样品中天然表面活性化合物的水平较低或未检测到，但可以通过添加营养物质来刺激生物表面活性剂的产生。添加已知的生物表面活性剂产生芽孢杆菌菌株和营养物质可以增加生物表面活性剂的产生。产生脂肽生物表面活性剂（例如 srfA3/licA3 基因）的遗传潜力很普遍，并且营养物质的添加刺激了来自不同储层的盐水产生生物表面活性剂，这表明生物刺激法用于生物表面活性剂介导的采油在技术上可能是可行的。
